Deploying hybrid cloud email: What you need to know

Matthew W. Cain |
Nov. 8, 2011

Email/calendar systems are the most important communications channels for enterprises, and deliver a reliable, cost-effective and secure mechanism for collaboration. An email system is typically used for a decade before suppliers are changed: organizations should apply significant due diligence in selecting an email system, given the criticality of email to their overall health.

Email/calendar systems are the most important communications channels for enterprises, and deliver a reliable, cost-effective and secure mechanism for collaboration. An email system is typically used for a decade before suppliers are changed: organizations should apply significant due diligence in selecting an email system, given the criticality of email to their overall health.

Companies are hearing the "siren song" of cloud email and, despite its immaturity, pressure is on organizations to tap into what is perceived to be a superior provisioning model to on-premise deployments. While cloud email is still in its infancy -- at three per cent to four per cent of the overall enterprise email market -- we expect it to be a growth industry, reaching 20 per cent of the market by year-end 2016, and 55 per cent by year-end 2020.

Escalating demand for hybrid model

That said, the cloud model for email services has not been suitable for many organizations that look for flexibility to support custom deployments. Organizations are also looking for systems with the ability to meet specific security, content control and application integration needs. Consequently, we see escalating demand for hybrid models -- where some mailboxes "live" in the cloud and others are located on premises.

A hybrid model helps organizations cope with the immaturity of the cloud model, while still allowing some use of the cloud. In a hybrid model some mailboxes live on-premises and some in the cloud, and it relies upon a user segmentation model, where different email services are offered to users based on need, as opposed to offering the same email to all users.

It has been our experience that running a hybrid model using different vendors results in complications for directory synchronization, help desks, format translation and policy enforcement. Dual-vendor deployments can also lead to a lack of interoperability for features such as calendaring. Dual-vendor hybrid models, therefore, are generally best avoided.

At this point, however, hybrid email models are in their infancy. Microsoft, for example, is only now offering rich coexistence between premises-based and cloud-based deployments. Given its infancy, then, organizations must be very careful when contemplating using a hybrid model.

The following are some of the important considerations when considering hybrid models:

User provisioning -- Large organizations have built very efficient processes for account creation of email services. Those processes will need to be extended to support cloud-based email services.

Management -- A single console for managing both on-premises and cloud email is required for efficiency and consistency of management and administration. Scripting services for bulk changes need to be supported across both provisioning models.

Single sign-on -- The ability for a user to authenticate to a local directory and have the credentials to enable access to the cloud email service is required.